US20020089599A1 - Illumination and image acquisition system - Google Patents

Illumination and image acquisition system Download PDF

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Publication number
US20020089599A1
US20020089599A1 US09/756,281 US75628101A US2002089599A1 US 20020089599 A1 US20020089599 A1 US 20020089599A1 US 75628101 A US75628101 A US 75628101A US 2002089599 A1 US2002089599 A1 US 2002089599A1
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US
United States
Prior art keywords
flash
lights
color
flash lights
luminance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US09/756,281
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English (en)
Inventor
Hermann Menning
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ORBOTECH - SCHUH & Co KG GmbH
Original Assignee
ORBOTECH - SCHUH & Co KG GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to IL13281799A priority Critical patent/IL132817A/xx
Priority to TW088121489A priority patent/TW429329B/zh
Priority to EP00123944A priority patent/EP1098190A3/en
Application filed by ORBOTECH - SCHUH & Co KG GmbH filed Critical ORBOTECH - SCHUH & Co KG GmbH
Priority to US09/756,281 priority patent/US20020089599A1/en
Assigned to ORBOTECH - SCHUH GMBH & CO. KG reassignment ORBOTECH - SCHUH GMBH & CO. KG ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MENNING, HERMANN
Publication of US20020089599A1 publication Critical patent/US20020089599A1/en
Abandoned legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/956—Inspecting patterns on the surface of objects
    • G01N21/95684—Patterns showing highly reflecting parts, e.g. metallic elements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/56—Cameras or camera modules comprising electronic image sensors; Control thereof provided with illuminating means
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/90—Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums

Definitions

  • the present invention relates generally to illumination and image acquisition systems and particularly to a color flash assembly for such systems.
  • AOI Automated optical inspection
  • PCB's printed circuit boards
  • bare i.e., which have no components mounted thereon
  • PCBs may be inspected after any step of assembly of components onto the PCB, such as after paste print, after component placement and/or after soldering.
  • AOI systems for inspecting populated PCBs employ various kinds of illumination at various positions around and above the PCB.
  • Color filters in cooperation with CCD cameras are typically used to acquire optical images of the PCB.
  • Other AOI systems employ color CCD cameras.
  • color camera systems generally operate by transmitting signals corresponding to one of three colors, typically red, green and blue (RGB). The frequency and phase of these signals are processed by color receiver circuitry, and must be registered properly with respect to each other in order to reproduce the transmitted picture as faithfully as possible.
  • the present invention seeks to provide a novel and elegant solution to the abovementioned problem of the art.
  • the present invention employs a plurality of color flash lights (typically three lights—red, green and blue) to illuminate the inspected article, and black-and-white cameras to acquire the optical images. Unlike color cameras, black-and-white cameras do not mutually register signals in different color spectra, and so the registration problems of the prior art are eliminated.
  • the colored-flash illumination of the inspected article is perceived by the black-and-white cameras in a highly accurate gray scale.
  • fast flashes of very intense light are employed such that the interval of image acquisition of the black-and-white cameras is longer than the flash time.
  • a control system is also provided for stabilizing and maintaining the illumination flashes at a constant and controlled level of luminance.
  • an illumination and image acquisition system including a plurality of color flash lights operative to illuminate an article to be inspected, and at least one black-and-white camera operative to acquire an optical image of the article as illuminated by the color flash lights.
  • the color flash lights include three differently colored lights.
  • the color flash lights include a red flash light, a green flash light and a hue flash light.
  • a flash time of the color flash lights is such that an interval of image acquisition of the at least one black-and-white camera is longer than the flash time.
  • a control system for stabilizing and maintaining color flashes of the color flash lights generally at a constant level of luminance.
  • the control system includes a flash power supply which powers the plurality of color flash lights, a light sensor in optical communication with the plurality of color flash lights, a processor in communication with the light sensor, the light sensor transmitting a signal containing information about a luminance of the color flash lights to the processor, the processor processing the information and providing a processed value, and a comparator in communication with the processor which compares the processed value with a control value for desired luminance, the comparator shutting down the flash power supply if the processed value is greater than or equal to the control value.
  • a method for providing light generally at a constant level of luminance including powering a plurality of flash lights, sensing characteristic light information of the flash lights, processing the information to arrive at a processed value of a luminance of the flash lights, comparing the processed value with a control value for desired luminance, and shutting down the flash lights if the processed value is greater than or equal to the control value.
  • FIG. 1 is a simplified pictorial illustration of an illumination and image acquisition system constructed and operative in accordance with a preferred embodiment of the present invention.
  • FIG. 2 is a simplified block diagram of a control system for stabilizing and maintaining color flashes of flash lights at a constant level of luminance, constructed and operative in accordance with a preferred embodiment of the present invention, useful with the illumination and image acquisition system of FIG. 1.
  • FIG. 1 illustrates an illumination and image acquisition system 100 constructed and operative in accordance with a preferred embodiment of the present invention.
  • System 100 is particularly suited for inspecting various assembly steps of a PCB.
  • System 100 preferably includes a plurality of lights spaced about and/or above an article 40 which is to be inspected, such as a PCB.
  • the plurality of lights may include, for example, eight flash lights illuminating at a relatively low level of illumination 1 , 2 , 3 , 4 , 5 , 6 , 7 and 8 , and eight flash lights illuminating at a relatively high level of illumination 9 , 10 , 11 , 12 , 13 , 14 , 15 and 16 , spaced generally equally about article 40 ; four central flash lights 17 , 18 , 19 and 20 , spaced generally equally overhead and close to article 40 ; four diffuse flash lights 21 , 22 , 23 and 24 spaced generally equally about article 40 ; and a line projector 25 positioned near article 40 . It is appreciated that all of the lights may be placed at any convenient height and angle with respect to article 40 as required, and that any other number or variety of lights may be employed
  • a plurality of color flash lights 26 , 27 and 28 are provided which illuminate article 40 .
  • Color flash lights 26 - 31 may be high intensity flash lights, e.g., xenon flash lights.
  • each plurality of color flash lights includes three differently colored lights, namely, red flash lights 26 and 29 , green flash lights 27 and 30 , and blue flash lights 28 and 31 .
  • the two pluralities of lights may be arranged such that one or more identical colors generally face each other (e.g., green flash lights 27 and 30 ), or that different colors generally face each other (e.g., red flash light 26 and blue flash light 31 , or red flash light 29 and blue flash light 28 ).
  • Illumination and image acquisition system 100 preferably includes one or more black-and-white cameras, such as cameras 42 , 44 , 46 and 48 , spaced generally equally about and above article 40 , and optionally, an array of one or more cameras above article 40 , such as cameras 49 , 50 , 51 and 52 , for example. It is appreciated that all of the black-and-white cameras may be placed at any convenient height and angle with respect to article 40 as required and that any other number of black-and-white cameras may be employed as well.
  • the black-and-white cameras 42 , 44 , 46 , 48 , 49 , 50 , 51 and 52 acquire a sequence of optical images of article 40 as illuminated by the flashes 1 - 25 and color flash lights 26 - 31 .
  • the flash time of the flash lights is preferably very fast, such that an interval of image acquisition of the black-and-white cameras is longer than the flash time of the flash lights.
  • the images acquired by cameras 42 , 44 , 46 , 48 , 49 , 50 , 51 and 52 are sent to a computerized image processor (not shown that processes and analyzes the images to determine defects on the PCB.
  • the colored-flash illumination of article 40 is perceived by the black-and-white cameras in a highly accurate gray scale with accurate and sharp contrast, thereby providing a highly accurate AOI system which is less expensive than AOI systems with color cameras. Moreover, the color registration problem of such color camera systems is substantially eliminated because the same black-and-white camera acquires, in temporal sequence, red, green and blue images which may, be precisely registered to obtain a color image as desired.
  • FIG. 2 illustrates a control system 60 for providing light generally at a constant level of luminance, constructed and operative in accordance with a preferred embodiment of the present invention, and useful with the illumination and image acquisition system 100 of FIG. 1.
  • Control system 60 may be used to stabilize and maintain a generally constant level of luminance for flashes 1 - 25 and color flashes 26 - 31 (FIG. 1).
  • a plurality of flash lights such as lights 61 , 62 , 63 and 64 , are connected to and powered by a flash power supply 66 .
  • Flash lights 61 , 62 , 63 and 64 are preferably xenon flash lights which are triggered by a trigger pulse 68 .
  • Flash lights 61 , 62 , 63 and 64 are preferably connected by fiber optic cables (or any other suitable optical waveguide) 71 , 72 , 73 and 74 to a light sensor 75 (more than one light sensor may also be employed).
  • Light sensor 75 transmits a signal containing information about a luminance of the flash lights 61 , 62 , 63 and 64 , as a function of time, to a processor 76 .
  • the luminance is defined as the luminous intensity in a given direction of a small element of surface area divided by the orthogonal projection of this area onto a plane at right angles to the direction.
  • the luminous intensity is a measure of the amount of light that a point source radiates in a given direction, and is expressed by the luminous flux leaving the source in that direction per unit of solid angle.
  • Processor 76 integrates the time function of the luminance of the flash lights and the integrated value is sent to a comparator 78 which compares the integrated value with a control value for desired luminance. As soon as the integrated value reaches or exceeds the control value, flash power supply 66 is signaled by comparator 78 to shut down, thereby stabilizing and maintaining the flashes of the flash lights 61 - 64 at a generally constant level of luminance. Control system 60 thus acts as a feedback to flash power supply 66 for maintaining a constant level of luminance.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Analytical Chemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
  • Spectrometry And Color Measurement (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)
  • Image Input (AREA)
  • Color Television Image Signal Generators (AREA)
US09/756,281 1999-11-08 2001-01-09 Illumination and image acquisition system Abandoned US20020089599A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
IL13281799A IL132817A (en) 1999-11-08 1999-11-08 Illumination and image acquisition system
TW088121489A TW429329B (en) 1999-11-08 1999-12-08 An illumination and image acquisition system and a method for providing light generally at a constant level of luminance
EP00123944A EP1098190A3 (en) 1999-11-08 2000-11-03 Illumination and image acquistion system
US09/756,281 US20020089599A1 (en) 1999-11-08 2001-01-09 Illumination and image acquisition system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IL13281799A IL132817A (en) 1999-11-08 1999-11-08 Illumination and image acquisition system
US09/756,281 US20020089599A1 (en) 1999-11-08 2001-01-09 Illumination and image acquisition system

Publications (1)

Publication Number Publication Date
US20020089599A1 true US20020089599A1 (en) 2002-07-11

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Family Applications (1)

Application Number Title Priority Date Filing Date
US09/756,281 Abandoned US20020089599A1 (en) 1999-11-08 2001-01-09 Illumination and image acquisition system

Country Status (4)

Country Link
US (1) US20020089599A1 (xx)
EP (1) EP1098190A3 (xx)
IL (1) IL132817A (xx)
TW (1) TW429329B (xx)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030189665A1 (en) * 2002-04-04 2003-10-09 Fuji Photo Film Co., Ltd. Image acquiring method and image acquiring apparatus
US20060110145A1 (en) * 2003-03-28 2006-05-25 Fujitsu Limited Image taking device, method for controlling light sources and computer program
US20070205357A1 (en) * 2006-03-03 2007-09-06 Fujitsu Limited Image capturing apparatus
US20070206114A1 (en) * 2006-03-03 2007-09-06 Fujitsu Limited Image capturing apparatus
US7706638B1 (en) * 2004-04-26 2010-04-27 National Semiconductor Corporation System, apparatus and method for color machine vision with black and white photoelectric sensor
US20110316978A1 (en) * 2009-02-25 2011-12-29 Dimensional Photonics International, Inc. Intensity and color display for a three-dimensional metrology system
WO2014101304A1 (zh) * 2012-12-27 2014-07-03 深圳市华星光电技术有限公司 显示面板的缺陷检测方法及其检测装置
US11768423B2 (en) 2020-07-23 2023-09-26 Beijing Xiaomi Mobile Software Co., Ltd. Image acquisition apparatus, electronic device, image acquisition method and storage medium

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6781687B2 (en) 2002-09-26 2004-08-24 Orbotech Ltd. Illumination and image acquisition system
CN101150732B (zh) * 2006-09-20 2010-08-11 王锦峰 用黑白相机拍摄彩色图像的成像方法和装置
JP2010512535A (ja) 2006-12-12 2010-04-22 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ 細胞分析方法及び装置
JP2010514046A (ja) 2006-12-19 2010-04-30 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ デジタル画像の取得のためのカラーシーケンシャルフラッシュ
FR2920227B1 (fr) * 2007-08-24 2009-11-27 Vit Procede d'inspection de cartes electroniques par analyse multispectrale.
CN103234476B (zh) * 2013-04-01 2014-04-02 廖怀宝 物体二维轮廓识别方法
JP6348289B2 (ja) * 2014-01-31 2018-06-27 株式会社Ｓｃｒｅｅｎホールディングス 検査装置および検査方法
CN110475036B (zh) * 2019-06-28 2021-08-27 佛山市景瞳科技有限公司 一种多谱段陶瓷光谱还原系统及方法

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US4546379A (en) * 1983-04-21 1985-10-08 Welch Allyn, Inc. Independent color adjustment for a video system
US4561731A (en) * 1980-03-10 1985-12-31 Kley Victor B Electronic illumination control
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US6567078B2 (en) * 2000-01-25 2003-05-20 Xiroku Inc. Handwriting communication system and handwriting input device used therein
US20030133021A1 (en) * 1997-07-24 2003-07-17 Toshihiro Hamamura Camera having improved image quality

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US4972093A (en) * 1987-10-09 1990-11-20 Pressco Inc. Inspection lighting system
JPH0658731A (ja) * 1992-06-11 1994-03-04 Fujitsu Ltd パターン検査装置
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US6022124A (en) * 1997-08-19 2000-02-08 Ppt Vision, Inc. Machine-vision ring-reflector illumination system and method
US6603103B1 (en) * 1998-07-08 2003-08-05 Ppt Vision, Inc. Circuit for machine-vision system

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US4561731A (en) * 1980-03-10 1985-12-31 Kley Victor B Electronic illumination control
US4354749A (en) * 1980-09-03 1982-10-19 Olympus Optical Co., Ltd. Endoscopic photographing apparatus
US4546379A (en) * 1983-04-21 1985-10-08 Welch Allyn, Inc. Independent color adjustment for a video system
US5185638A (en) * 1991-04-26 1993-02-09 International Business Machines Corporation Computer controlled, multiple angle illumination system
US20030133021A1 (en) * 1997-07-24 2003-07-17 Toshihiro Hamamura Camera having improved image quality
US6443638B1 (en) * 1999-06-25 2002-09-03 Fuji Photo Film Co., Ltd. Exposure control apparatus used for a camera
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US6552783B1 (en) * 2000-06-28 2003-04-22 Teradyne, Inc. Optical system

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030189665A1 (en) * 2002-04-04 2003-10-09 Fuji Photo Film Co., Ltd. Image acquiring method and image acquiring apparatus
US7336314B2 (en) * 2002-04-04 2008-02-26 Fujifilm Corporation Image acquiring method and image acquiring apparatus
US7415202B2 (en) * 2003-03-28 2008-08-19 Fujitsu Limited Image taking device, method for controlling light sources and computer program
US20060110145A1 (en) * 2003-03-28 2006-05-25 Fujitsu Limited Image taking device, method for controlling light sources and computer program
US7706638B1 (en) * 2004-04-26 2010-04-27 National Semiconductor Corporation System, apparatus and method for color machine vision with black and white photoelectric sensor
US7679671B2 (en) 2006-03-03 2010-03-16 Fujitsu Limited Image capturing for capturing an image of an object by illuminating the object and receiving light from the object
US20070206114A1 (en) * 2006-03-03 2007-09-06 Fujitsu Limited Image capturing apparatus
US20070205357A1 (en) * 2006-03-03 2007-09-06 Fujitsu Limited Image capturing apparatus
US7728905B2 (en) * 2006-03-03 2010-06-01 Fujitsu Limited Image capturing apparatus having an image capturing system disposed close to an illumination system
US20110316978A1 (en) * 2009-02-25 2011-12-29 Dimensional Photonics International, Inc. Intensity and color display for a three-dimensional metrology system
CN102334006A (zh) * 2009-02-25 2012-01-25 立体光子国际有限公司 用于三维计量系统的强度和彩色显示
CN104990516A (zh) * 2009-02-25 2015-10-21 立体光子国际有限公司 用于三维计量系统的强度和彩色显示
WO2014101304A1 (zh) * 2012-12-27 2014-07-03 深圳市华星光电技术有限公司 显示面板的缺陷检测方法及其检测装置
US11768423B2 (en) 2020-07-23 2023-09-26 Beijing Xiaomi Mobile Software Co., Ltd. Image acquisition apparatus, electronic device, image acquisition method and storage medium

Also Published As

Publication number Publication date
IL132817A0 (en) 2001-03-19
IL132817A (en) 2003-11-23
TW429329B (en) 2001-04-11
EP1098190A2 (en) 2001-05-09
EP1098190A3 (en) 2002-01-16

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Date Code Title Description
AS Assignment

Owner name: ORBOTECH - SCHUH GMBH & CO. KG, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MENNING, HERMANN;REEL/FRAME:011432/0830

Effective date: 20001228

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION